Reliable High Discharge Lipos

[Eventorizon]

I am looking for a fairly low capacity lipo, say 2500-3500mAh, that can do discharge rates of about 240A. (So for a 2500mAh battery it would need to do 100C, or a 3500mAh would need 70C). As you know there are loads of lipo brands out there but which are reliable, safe and long lasting.

The ones I have seen have been...
VoltON
Desire Power
Turnigy
Venom
Thunderpower
Poweredge

What experience or rumours have people heard about these different lipo brands. I am currently using Gens Ace lipos but they dont seem to do a Lipo with a low capacity that does a high enough discharge rate.

Note: I know its a little mad but I don't want to give away the details if this new design turns out to be viable! :wink:

[PJ-27]

Re: Reliable High Discharge Lipos

I'm sure you have your reasons, but why not just up the capacity? Would be the easiest solution.

I use FlightPower Li-Pos, seem pretty popular.

[Eventorizon]

Re: Reliable High Discharge Lipos

Its partially to do with size; bigger capacity, bigger battery, and you end up with left over power. I ran 4 fights at GSL on my 4000mAh drive battery without recharging. I recharged after the 1st fight but the charger could only put 600mAh back into the battery. (well I was only in the area for 1.5 mins not 3)

[PJ-27]

Re: Reliable High Discharge Lipos

Theoretically the bigger capacity you have, then the larger continuous current you can deliver for a lower C rating.

Helpfully the Flightpower website has Continous and Burst ratings for all it's batteries do you don't have to do the maths.

An alternative would be to have 2 batteries running in parallel, gives you more options for space. But what on earth do you want with 240a!?

[archie2000]

Re: Reliable High Discharge Lipos

240amp 3.5amp that won't last a fight will it?
I also found this http://www.giantshark.co.uk/gens-5000ma ... 06494.html
which is expensive

[typhoon_driver]

Re: Reliable High Discharge Lipos

what do you need 250 amps for and at what voltage?

[Laser]

Re: Reliable High Discharge Lipos

try OPTIpower lipos their some of the best lipos on the market

[Eventorizon]

Re: Reliable High Discharge Lipos

I need a 4 cell, 14.8V, though the motors nominal is 12V...

The motors pull just under 20A at their most efficient, but with the loading they will be under I doubt I will get anywhere near that...

I have found a 4 Cell 4000mAh 50C on the Gens Ace site but its germany only for some reason...

This is still just an idea, it may not even work but hey, we like to set ourselves a challenge!

[typhoon_driver]

Re: Reliable High Discharge Lipos

Once again I'll ask, why do you need 250amps?

[blazerbotics]

Re: Reliable High Discharge Lipos

How long do you need to pull the 240amps for? Could you have a bank of capacitors in there to give the surge current?

[Eventorizon]

Re: Reliable High Discharge Lipos

I don't know how long really. The maximum draw of each motor is 120A so the idea is to make all that power available when pushing and driving rather than being prevented by the limits of the battery and ESC's.

I the basic idea is to make the most powerful and robust full body hammer possible. But I have given over 3Kg to a small disc system so when brute force isn't enough we can turn around and use that.

Think a featherweight Tornado and then imagine what happens when you devote over a third of the robots weight to the motors and gearbox's in a featherweight. I think Tornados weight distribution was similar to that in its first iteration without the disc.

[mattsdragons]

Re: Reliable High Discharge Lipos

Bloody hell, what motors are you using?!?!?!

[Ellis]

Re: Reliable High Discharge Lipos

Why not make just that: a FW Tornado? Same weapon configuration and everything? Do it do it do it do it!

Also, as I am sure you are aware, power is useless unless it can be put down. I am assuming you'll deal with that with magnets?

[ewan]

Re: Reliable High Discharge Lipos

You shouldn't be reaching anywhere near 1776W (120 x 14.8V) with even the most powerful featherweight drives - you're fundamentally limited by how much traction you can get on the floor as to how much you'll be able to use before you spin the wheels (unless you're using magnets?) - might be useful to have a play around with this http://www.architeuthis-dux.org/torquecalc.asp


edit: looks like someone was a minute ahead of me!

[Eventorizon]

Re: Reliable High Discharge Lipos

Assuming I have set up the calculator right says that when I get to 30A of a possible 133A the wheels will spin. and I need 86 oz-in to spin the wheels or 6250g/cm... can someone explain what that actually means beside i have WAY to much power